Acid gas-induced fabrication of hydrophilic carbon nitride with dual defects for boosting photocatalytic H2O2 generation and contaminants degradation

Abstract

An acid gas-induced strategy was proposed to fabricate a series of PCNs with dual-defects and surface hydroxyl group (DDH-PCNs) for photocatalytic H₂O₂ generation and trace organic contaminants (TrOCs) degradation. The Nv can accelerate the O₂ adsorption and activation by formation a bridge C−O−O−C model. Accompanied cyano groups provide the asymmetric electron distribution for carriers’ separation. Moreover, the surficial hydroxyl groups provide more protons for photocatalytic H₂O₂ production. As a result, the DDH-PCNs showed an excellent photocatalytic H₂O₂ rate of 5554.6 μmol g⁻¹ h⁻¹ under full spectrum irradiation, and it can also degrade SMX (100 μg/L) completely in 5 min. Notably, the optimal DDH-PCN(1.6) can simultaneously achieve photocatalytic H₂O₂ production and SMX degradation in a wastewater/alcohol system. The rapid formation of the intermediate superoxide radical (2.44 min⁻¹) is the key to above dual functions. Our findings provide profound insights into ·O₂⁻ manipulation and development of dual functional photocatalytic system towards environmental application.